They are not all Christianity. Theres reason they all have different names, and being Catholic is much different then being Christian. I know, I was baptised catholic, but gave up on it later. Technicly(sp..) I am catholic, but I believe more of what the Christians believe in. Catholic rules differ alot from Christian. So do some beliefs and traditions. No they are not all the same, and no they are not all grouped under "Christianity".